Research Of LD Pump High-power Solid Laser With Plano-convex Resonator

High power solid-state lasers is widely applied to laser material processing field for several advantages. The wavelength in the IR can be transmitted by fiber. The peak power is higher and the system is rather compact. With the continuous improvement of the pump power, the thermal lens effect appeared gradually and almost affects to the laser performance in all its aspects. For example, the stability of resonant cavity, cavity size, the quality of output beam, mode coupling, and so on. Thermal lens effect is considered by the chief factor in the high power laser system designing. There are several ways to eliminate the thermal lens effect, such as cooling, filtering,the concave end and so on, but the effect is not prominent in high power period. Plano-convex resonator is produced by a new idea to reduce the thermal lens effect in this paper.By using the effect of rods in high power state can be equivalent to a optical lens,plano-convex resonator use convex mirror as the reflector to get parallel beam in the output mirror. The article does research and analysis data about output power, divergence angle and the thermal focal length, which experiment on the flat bar flat cavity,the concave end cavity, flat bar plano-convex resonators. It calculates the stability and divergence angle using the method of ABCD matrix, and the conclusion almost conforms to the experiment result. Research shows, convex cavity stability is better than the others, the effect is good on the thermal lens effect compensation.In the foundation of above experiments, it takes a experiment of laser roller texturing on the YAG laser with plano-convex resonator, and analyzed the result between the flat rod laser and the shave rod laser. Under the conditions of the plane convex cavity, the laser is better than the others, and received tunable roughness in a wide range. It provides a good basis for laser processing.